Apparatus for use in rectifying cylinder bores



Aug. 17 ,1926. A y c.` FoRNAcA APPARATUS FOR USE IN RECTIFYING CYLINDER BORES Filed July 18., 2 Sheets-Sheet 2 Patented Aug. 17, 1926.

GUIDO FORNACA,

ICE.

.or TURIN, rrALY.

APPARATUS 4FOR USE IN RECTIFYING CYLINDR'BORES.

Application filed July is, 1924, semi No. vasellame vninaiy December ao, 1923.

This invention relates to apparatus for use in rectifying cylinder bores, of the kindhaving a plurality of grinding or cutting tool spindles, one for each cylinder, adapted to be given combined movements of rotation and orbital revolution.l

I provide an improved and simplified apparatus of this kind characterizediby a central operating arrangement for producing these movements. Said arrangement comprises, a shaft operatively connected to the tool spindles and mounted in a sleeve forming part of a carriage supporting the spindles.

The apparatus may be applied direct to the usual rectifying machine, having a head which provides for rotation of the shaft and eccentric or orbital revolution of the sleeve,

after dismounting the single mandrel tool holder with which such machines are provided; or it may form part of a specially constructed machine.

The accompanying drawing shows, by way of example, a form of the apparatus suitable for rectifying simultaneously the four cylinders of a mono-block internal combustion engine.

Fig. 1 is a front elevation of the apparatus shown partly in section onthe line 1 1 Aof Fig. 2.

Fig. 2 is a section on the line 2-2 of Fig. 1.

Fig. 3 is a section on the line 8 3 of Fig. 1.

Fig. 4 is a diagrammatic longitudinal vertical section of the apparatus applied to an ordinary grinding machine.

In the drawing, 1 indicates a frame upon which is mounted for vertical sliding movement a carriage 2 balanced by means of a counterweight 3 movable on an arm of a lever 15 hinged at 16 to the support 4 and having its other arm connected, by means of a link l17 to the carriage 2. Mounted for ,horizontal sliding movement on thevcarriage y 2 is an auxiliary carriage 5 retained in place by strips 6, and projecting from thecar riage 5 are sleeves 7 intended to support the shafts 8 of the grinding tools. The carriage 5, being combined with the carriage 2, can be displaced in any direction while remaining parallel to itself, after the manner of an Oldham joint.

The shafts 8 are mounted in adjustable sleeves 18; the innerV end 19 of each shaft is square in cross section and engages in a cavity of corresponding form ina toothed wheel 9 carried by shafts. 20. The'wheels 9` engage with transmission pinions 10; moreover the intermediate wheels 9 engage with a main driving'wheel 11, which latter `is keyed on a shaft 12 mounted in afsleevev 13, while at lthe outer ends said vshaftsv V8 carry thegrinders 14.

Referring especially to Fig. 4 `showing diagrammatically a grinding machine pro-- vided with this arrangement the sleeve 13 is eccentrically connected by means of sleeveV ed on a carriage 27 movable in an axial direction, of the grinding machine.

Owing to the eccentricity of the head of the rectifyingmachme there is imparted Ato the sleeve 13 a movement of revolution which movement is transmitted to the car-l riage 5, the sleeves 7, all the shafts 8, and the gears 9. At the same time the latter receive from the machine shaft 24 connected to 12 a rapid movement of rotation. The grinding tools keyed on the shafts 8 are thus actuated by two combined movements of rotation and revolution. The orbits of rev olution described by the sleeves 7 (and by the grinding tools) of necessity are all equal and their diameter will be determined by the eccentricity of the machine head and it will be adjustable if the eccentricity is adjustable.

The apparatus is described and represented in the `drawing for operation from a horizontal shaft, but it may be arranged for operation from a vertical shaft and the latter arrangement may even be the most rational if a machine is expresslyl built for the purpose of carrying out the invention.

In this case the counterweight 3 may be omitted, as the carriages willr then move in horizontal planes. Of course, other modifications can also be made without departing from the spirit or scope of the invention.

l/Vhat I claim is:

1. An apparatus for rectifying a plurality of cylinder bores comprising a casing, a plurality of spindles carrying abrasive Wheels mounted in the latter, one' for each cylinder, and a central koperating mechanism for simultaneously imparting a rotary and orbital revolution to the spindles.

2. A11 apparatus for rectifying cylinder bores, comprising av plurality of spindles carrying abrasive Wheels one for each cylinder, a carriage supporting the spindles, a sleeve forming part of the carriage, a shaft rotatably mounted in the sleeve operatively connected to the spindles, and means for imparting an orbital movement to the sleeve.

3. An apparatus for rectifying cylinder bores, comprising two carriages movable in directions perpendicular' to each other, a plurality of spindles carrying abrasive Wheels mounted in one of the carriages, a sleeve forming part of said carriage adapted to be rotated eccentrically to produce orbital 20 revolution of the spindles, gears connecting the spindles'for simultaneous rotation, and a shaft rotatably mounted inthe sleeve for transmitting rotary motion to all the spindles through said gears.

4.. An apparatus for rectifying cylinder bores comprising a, vertically movable carriage, an auxiliary carriage, horizontally movable on the latter, a plurality of spindles carrying abrasive Wheels journaled in the auxiliary carriage, a pinion on each spindle, a sleeve mounted in the auxiliary carriage, a shaft rotatably journaled in the sleeve, a

gear on Vthe shaft, gearingy operatively connecting said gear with the pinions, and means for imparting an orbital movement to said sleeve.

In testimonythat I claim the foregoing as my invention, I have signed my name.

GUIDO rouwen 

